uncertainty of conditions for many reservists. The 1991 Gulf War and, in particular, OEF and OIF have occasioned the increased activation of reserve and National Guard units to supplement the all-volunteer military. Those units and the military in general also have more women serving and have women serving in more occupations than ever before. In the Vietnam War, 3,143,645 men and 7166 women served in the Vietnam theater. The military during the Vietnam era was about 87% white, 11% black, and 5% Hispanic (Kulka et al. 1990). About 75% of those who served in the Vietnam theater were volunteers and 25% were draftees; in World War II, 66% were draftees (MRFA 2007). The average age of a U.S. enlisted soldier was 26 years in World War II and about 21 years in Vietnam (25-27 years for all military personnel serving in Vietnam) (Schlenger 2007). Only very small percentages of the soldiers in World War II and the Vietnam War were in the reserves or National Guard.
Of the nearly 700,000 U.S. troops who fought in Operation Desert Shield and Operation Desert Storm in 1990-1991, almost 7% were women and about 17% were in activated National Guard and reserve units. Military personnel, with a mean age of 28 years, were, overall, older than those who had participated in previous wars. Some 70% of the troops were white, 23% were black, and 6% were Hispanic or other (DoD 1994). As of 2005, 14% of the almost half-million active-duty Army personnel were women, as were 23.2% of Army reserves and 12.8% of Army National Guard. The proportion of Hispanics in the Army increased from about 4% in 1985 to 11% in 2005, and the proportion of blacks decreased in the same period from 27% to 22% (U.S. Army 2007).
Given the committee’s charge from the VA—to assess the long-term health effects of deployment-related stress—the committee began by defining deployment-related stress as deployment to a war zone. Combat is one of the most potent stressors that a person can experience, but as military conflicts have evolved to include more guerilla warfare and insurgent activities, restricting the definition of deployment-related stressors to combat may fail to acknowledge other potent stressors experienced by military personnel in a war zone or in the aftermath of combat (King et al. 2006). Such stressors encompass an enormous array of physical and psychologic events, including constant vigilance against unexpected attack, the absence of a defined front line, the difficulty of distinguishing enemy combatants from civilians, the ubiquity of IEDs, caring for the badly injured or dying, duty on the graves registration service, and being responsible for the treatment of prisoners of war. The deployment stressors associated with any armed conflict also include noncombat stressors. Non-combat-related stressors that might be experienced by deployed personnel are separation from family, friends, and colleagues; loss of or reduction in income; and concern over employment status when deployment ends (O’Toole et al. 1999). Therefore, the committee considered that military personnel deployed to a war zone, even if direct combat was not experienced, have the potential for exposure to deployment-related stressors that might elicit a stress response and that the emotional and physical reactions of military personnel to those stressors can vary widely. The committee recognized that factors other than deployment-related stressors can affect the outcome of exposure to potential stressors, including the stress response itself and individual risk and protective factors.
The stress response is a coordinated set of interactions among multiple organ systems in the body, including the brain, gut, heart, liver, immune system, thyroid, adrenals, pituitary, gonads, bone, and skin. Acute stress responses are usually adaptive, preparing the organism for